Speed changing transmission mechanism



Jan. 8, 1935. J. REILLY 1,987,518

SPEED CHANGING TRANSMISSION MECHANISM Filed July 28, 1935 2 Sheets-Sheet l 17a-hz.

Jan. 8, 1935.

J. L. REILLY SPEED CHANGING TRANSMISSION MECHANISM Filed July 28, 1933 2 Sheets-Sheet 2 .30 d0 g 44 45 /f/A la) .92

Patented Jan. 8, 1935 UNITED SPEED cHANGrNG TRANSMISSION MECHANISM.

y JohnL. Reilly, Springfield; Vt. application. July 4its, .19%,A serial. No. 682,613.

z Clarins.V (ci. 'i4- 571).

A further object is to` provide a construction in which the endthrust ofthe associated parts willbe effectively counterbalanced, so thatno un- 152 `balanced endwisev forces will require counteraction.

Morespecically, Iv provide a construction in which power is transmittedy through compound eccentrics, andI provide means by which said 20 compound eccentrics may be `conveniently adjusted.- during the operation of the mechanism,

thereby varying the amount of eccentric throw and permitting theplacing 0f theeccentric meme bers; in neutral position-,when desired.

My invention further relates'toarrangementsand". combinations ofA parts which will be hereinafter described andimoreparticularly pointedout inthe appended claims.

Apreferrecl form o-fitheinvention is shown in 30` the drawings, in which.

Fig.; 1 is a' plan View, partly insection, showing my improved., transmission mechanism;

Fig. 2 is aisectional elevation, taken alongv the` line 2--2 in'Fig; 1,.and

the eccentric members adjusted to neutral position.

Referring to the. drawings, my improved transmissionmechanism comprises a driving member` 40110- (Fig. 1) rotatable in an anti-friction bearing.: l11k and.` having: an -eccentrically positioned: recess-L '-12V to receive one. end ofr a speed-adjustiiigv shaft` 13.. The shaft 13 isl provided. with a` series ofl straight splines l4extending through a broached opening. in tl'le'endA wall` 15` of they driving mem'- bei" 10.

Additional bearing members 16v and 1.7 'aresupported in bearings 18'and 19 alignedV with the 50, bearing- 11. The bearing'member 17- has an ec centric'recess 20 toreceive a portion of the shaft 13 andalso has the same straight splined connection between a portion of, the shaft and theY outer. .endfwall of: the member 17. ThebearingI 55.,.member- 16"'If1as` an' eccentric recess 22 extending Fig. 3.. is. aview similar-to. Fig. 2 but--showingtherethrough. andv also-.basi a; keywayf 23. at: one: sideito recevefa pin;24f.inJ the; shaft: 13;;

The.: driving; member: 10. and. end .bearingzmeme ber" 17A are;v maintainediin .denitef angularrelaf tioniby. the straight splines omtlref,shaft 13;,and11 5 the.;in'termediateY bearing member 1liis:- maine tainedy in: then same angular; relation; by thee keyway 23 and pin 14. It will be noted,.however;. that thezdriving member; 10..andfbcaring. members 16. and: 17. are sdconnectedpto. the Shaftil'that( l0 free l axial movement of.: the shaft. 13,is-perznittem` A.- flange or, enlargementlv 251: is formed at; one4 end of the shaft 13 and is concentric withithe. driving and bearing members.10,16.and;17; This iiange, 25is groovedasvindicatedat 26ftoireceivee 15 blocks: 27; pivoted in. the-.endoff ai forked-hand-v lever 28j, which in turn.ismountedy on;a fixed: pivot 29. The shaft 13.. may,A thus. bemanuallw adiustedaxiallyfbyfthe hand.lever.-2. l y y A drivenvshaft 30. is-irotatable..in ilxedfbearingsv 20v 31 and-32 and is-.disposed'inparallel.relation.to.-. the axis of thezdriving.,andbearing members-10,. 16 and 17. Clutch members A40- (Fig: 2). are. splined to the driven Shaft, 30 and, are provided with aplurality of. outwardly curzvedcam.k surfaces 41, adapted` to. be; engaged by balls or rollsfezr whichare disposed..betweengthe.:camsnrfaces 4l and the cylindrical inner surfacesc44of,v outer clutch members-45..l Thesur-faces. 4l: and zifi-.cooperateto form ball-holding recessestaper.- ing gradually in thedirection Aof rotationof thek Y drivenshaft 30, asH indicatedby the. arrowfa. in..

Fig. 2.

Spring, followers 46.. may, be providedto` assist the seating. of. 'the baue or reus. 42,. which loans 355v f or rolls maybe of..successiv,ely reduced diameters corresponding to the.. taper of. tlieball-holdingIv recesses.

The outer clutchtmember's .45.` are freeto. move.

about the axis. of. theldrivenl shaftjSO andare.v 401'A provided .with arms 5.0,` Themembers are assembled. in,..reversed' pairs, so that the armsv5() extendi outwardv atloppositesides of the shaft The speed-changing shaft 13' (Fig. y1)` isprovided with right and left-hand' steep-.pitch heli# cal screw-threads. 52. and'15'3 vwhi'clrare threaded" into eccentricor crank members 54"and 55. These; members 54 and 55 are mounted; between the driving; and bearing members' v1'1, 1 8 and'l rand 50'* lar openings tir` receivewhardened steel bearing *555' of rolls 64.

Having described the details of construction of my improved transmitting mechanism, the method bearing members 16 and 17. So long as the shaft 13 remains in rlxed axial position, rotation of the driving member 10 will cause the 4members 54 and 55 to act exactly the same as ordinary crank-pins and the arms 50 will be oscillated as indicated by the arrows b in Fig. 2, thus causing the outer clutch members 45 Vof an associated pair to have corresponding oscillating movements but in reverse directions.

When the right-hand arm 50 in Fig. 2 is moving upward to cause the one-wayclutch to engage and advance the shaft 30 in the direction of the arrow a, the left-hand arm 50 will be moving in the reverse or clockwise direction and the corresponding clutch will be inoperative. Consequently the two clutch members of an associated pair alternately advance the shaft 30 one step each in the memberlO.

If the driving member 10 rotates relatively fast, the rotation of the driven shaft 30, although actually intermittent, Will be practically continuous, owing to the very slight intervals between forward impulses. l

If a reduction in speed of the driven shaft 30 is desired, the handle 28 is moved in the direction of the arrow cin Fig. 1 to slide the shaft 13 to the right. As the shaft 13 is splined and keyed to the driving member 10 and bearing members 16 and 17, the shaft cannot turn in said bearing members and the endwise movement of the shaft can only take place in conjunction with corresponding rotational movements of the eccentric or crank members 54 and 55.

The helical threads 52 and 53 are vof such steep pitch that the usual holding action of the nut does not occur and the eccentric members may be turned by reasonable endwise pressure on the shaft 13.

In the position of the parts shown in Fig. 2, the ecoentricity d of the crank member 54 is added to the eccentricity f of the shaft 13, thus giving the maximum eccentricity. The eccentric distances d and f are preferably equal.

It is obvious that any relative rotation of the crank members 54 and 55 about the axis of the shaft 13 will reduce the net or total eccentricity, and that when the members 54 and 55 have been given an angular adjustment of the eccentricity of the crank members 54 and 55 and thel shaft 13 will offset each other, so that the crank members will be in neutral position and in alignment with theaxis of the driving member 10 arid bearing members 16 and 17 as shown in Fig. 3.

As the crank members 54 and 55 are angularly adjusted equally but in opposite directions, the impulses derived from these crank members will be applied at different rtimes to the driven shaft 30 except when set forl maximum throw. For slower speeds there will be four impulses for each revolution of the driving member 10, which impulses will be more or less equally spaced according to the eccentric setting.

I am thus able tosecure a continuous and progressive speed variation from maximum to `Zero by a single continuous movement of the hand lever 28 in one direction and a similar progressive speed increase by a reverse movement of the lever 28.

By providing the right and left-hand helical threads 52 and 53, I counterbalance the endwise thrust caused by the driving of the crank members 54 and 55 through these helical screw threads. 'I'he end thrusts of the members 54 and 55 thus offset each other and there is no unbalanced force tending to move the shaft 13 axially. Consequently the shaft remains naturally in any axial position to which it is adjusted, and no unbalanced end thrust need be overcome in adjusting the shaft axially to vary the speed.

While I have shown two sets of clutch members, it will be obvious that as many additional sets may be provided as may be necessary to transmit the required power, it being desirable, however, that an even number of sets be used so that all end thrusts may be counterbalanced.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as setforth in the claims, but what I claim is:-

1. Variable eccentric transmitting mechanism comprising a continuously rotated driving member, a fixed bearing forL said member, a speed changing shaft of circular cross section slidable axially in a longitudinal cylindrical opening in' said driving member of corresponding circular cross section, said longitudinal opening being positioned eccentrically with respect to the axis of said driving member, means to prevent relative rotation of said driving member and said speed changing shaft, said shaft having steep-pitch helical threads formed in a cylindrical portion thereof and encircling said shaft, a crank member mounted on said threaded portion of said speed changing shaft and having an eccentrically positioned cylindrical opening therein threaded to receive and engage said helical threads, means to prevent axial movement of said crank member, and means to move said speed changing shaft axially relative to said crank member along said eccentric cylindrical opening, thereby causing said crank member to be turned about the axis of said speed changing shaft and relative to said driving member, thereby varying the effective throw of said crank member.

2. Variable eccentric transmittmg mechanism comprising a continuously rotated driving member, a xed bearing for said member, a speedchanging shaft slidable axially in said driving member and positioned eccentrically with respect to the axis of said member, means to prevent relative rotation of said driving member and speedchanging shaft, said shaft having two sets of steep-pitch helical threads formed on spacedportions thereof and of opposite hands, crank members-mounted on said speed-changing shaft and each having an eccentrically positioned opening therein threaded to receive and engage one set of said helical threads, means to prevent axial move- Vment of said crank members, and means to move said speed-changing shaft axially relatively to said crank members, thereby turning said crank members in opposite directions relative to said speed-changing shaft and driving member and thus varying the effective throw of said crank members while counterbalancing the end thrusts between said speed-changing shaft and said crank membersv in all relative positions thereof.

JOHN L. REILLY. 

